code: def test_2d():
      B1, B2 = (gen_BrownianMotion() for _ in range(2))
      B1s = implemented_function("B1", B1)
      B2s = implemented_function("B2", B2)
      s, t = sympy.symbols(("s", "t"))
      e = B1s(s) + B2s(t)
      ee = lambdify((s, t), e)
      assert_almost_equal(ee(B1.x, B2.x), B1.y + B2.y)
  
file_path: nipy/nipy/modalities/fmri/tests/test_aliases.py
imports: import numpy
  import pytest
  import scipy.interpolate
  import sympy
  from numpy.testing import assert_almost_equal
  from sympy.utilities.lambdify import implemented_function, lambdify
label_desc: Use image node_id 5 for calling a global function with example usage: test_2d() without return types